AmiApache wrote:... when i try to access via browser to one of this folder, i.e. typying http://localhost/connect.php, i receive the 404 not found message....

That is the correct method to request the page you discussed. Therefore, we can only guess with a few ideas (as you haven't given any details on configuration changes). Perhaps your file was saved as something like connect.php.txt (you may need to ensure file extensions are shown), or that you changed your port away from the default 80 and aren't inserting your new port into your URL.